// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef NET_NQE_SOCKET_WATCHER_H_
#define NET_NQE_SOCKET_WATCHER_H_

#include "base/callback.h"
#include "base/memory/ref_counted.h"
#include "base/memory/weak_ptr.h"
#include "base/threading/thread_checker.h"
#include "net/socket/socket_performance_watcher.h"
#include "net/socket/socket_performance_watcher_factory.h"

namespace base {
class SingleThreadTaskRunner;
class TimeDelta;
} // namespace base

namespace net {

namespace {
    typedef base::Callback<void(SocketPerformanceWatcherFactory::Protocol protocol,
        const base::TimeDelta& rtt)>
        OnUpdatedRTTAvailableCallback;
}

namespace nqe {

    namespace internal {

        // SocketWatcher implements SocketPerformanceWatcher, and is not thread-safe.
        class SocketWatcher : public SocketPerformanceWatcher {
        public:
            // Creates a SocketWatcher which can be used to watch a socket that uses
            // |protocol| as the transport layer protocol. The socket watcher will call
            // |updated_rtt_observation_callback| on |task_runner| every time a new RTT
            // observation is available.
            SocketWatcher(SocketPerformanceWatcherFactory::Protocol protocol,
                scoped_refptr<base::SingleThreadTaskRunner> task_runner,
                OnUpdatedRTTAvailableCallback updated_rtt_observation_callback);

            ~SocketWatcher() override;

            // SocketPerformanceWatcher implementation:
            bool ShouldNotifyUpdatedRTT() const override;
            void OnUpdatedRTTAvailable(const base::TimeDelta& rtt) override;
            void OnConnectionChanged() override;

        private:
            // Transport layer protocol used by the socket that |this| is watching.
            const SocketPerformanceWatcherFactory::Protocol protocol_;

            scoped_refptr<base::SingleThreadTaskRunner> task_runner_;

            // Called every time a new RTT observation is available.
            OnUpdatedRTTAvailableCallback updated_rtt_observation_callback_;

            base::ThreadChecker thread_checker_;

            DISALLOW_COPY_AND_ASSIGN(SocketWatcher);
        };

    } // namespace internal

} // namespace nqe

} // namespace net

#endif // NET_NQE_SOCKET_WATCHER_H_